Piano and office chair



7 (No Model.) I

G. E. DAVIS.

PIANO AND OFFICE CHAIR. No. 343,626. Patented June 15,-1886.

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UNITED STATES PATENT OrricE.

CHARLES E. DAVIS, OF COLUMBUS, OHIO.

PIANO AND OFFICE CHAIR.

SPECIFICATION forming part of Letters Patent No. 343,626, dated June 15, 1886.

Application filed November 23, 1885. Serial No. 183,816. (No model.)

To all whom it may concern:

Be it known that I, CHARLES E. DAVIS, of Columbus, county of Franklin, State of Ohio, have invented or discovered a new and useful Improvement in Piano and Office Chairs; and I do hereby declare the following to be a full, clear, and concise description thereof, reference being had to the accompanying drawings, making a part of this specification.

My invention relates to improvements in chairs having a stationary seat and springback. The seat may have four legs, one in each corner, as a common chair, or it may be secured to a screw, as in piano and office chairs, having only a rotary motion, 'and not to chairs having a tilting seat, as in tilting chairs.

The object of my invention is to provide a chair having a back so arranged in connection with a spring that it conforms to different positions when it is occupied by a person sitting in the chair and leaning backward, thereby forming a back-rest. I attain this object by the mechanism illustrated in the accompanying drawings, in which Figure 1 represents a side (left) View of chair, dotted lines representing chair in position when occupied with back pressed backward. Fig. 2 represents bottom of chair as viewed from underneath.

Similar letters refer to similar parts throughout the different views.

A is a stationary seat; B, an arm, one part passing around parallel with edge of seat, the other part joining back abouthalf-way up from seat, both parts being fastened to back, both arm and back working on a pivot at side of seat, which passes through lower part of arm and directly into side edge of seat; 0, a cr0ss-piece secured to lower end of back I, and resting upon lever G; D, a concave plate secured to seat, in which screw H fastens with a set-screw. Plate D also has bearings M, in which lever G rests. E isa coil-spring, one end of which hooks over end of lever G, while other end hooks ever end of lever F, which has a bearing at N, as shown in Fig. 2.

To one arm of lever F is secured a rod, K, which extends through the chair-frame R at the side. One end of this rod is provided with a screw-thread and nut, O, which sets in an angular depression in one arm of the lever F, to prevent it from turning, and the opposite end is secured by means of a knob, J, rigidly attached thereto and bearing against the outer face of the chair-frame B. By turning the knob J to the right or left the thread upon the end of the rod operates within the nut O and varies the tension of the spring, for the purpose of increasing and diminishing the resistance to the back P.

L is a friction pin and plate, and rolls between lever G and crosspiece O.

I do not herein claim to be the inventor, broadly, of a chair having a stationary seat in combination with a back adapted to move in the arc of a circle, and provided with springs, whereby the back will conform to the different positions assumed by the occupant of the chair.

What I claim as my invention, and wish to secure by Letters Patent, is-

1. The combination, in a chair, of a stationmy seat, a back having arms pivoted to the sides thereof, said back being provided with a friction-pin adapted. to bear upon the arm of 7 5 a lever pivoted below the seat, one arm of the lever being attached to a spring, and the other arm adapted to form a support to said back, substantially as described.

2. The combination, in a chair, of a stationary seat, a back pivoted thereto, a lever, one end of which is adapted to support said back and the other end attached to a spring, and mechanism for regulating the tension of said spring, substantially as described.

O. E. DAVIS.

In presence of- CHAS. T. CLARK, S. HAMBLETON. 

